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Abstract:

Embodiments of setting an optimal image parameter for obtaining an
optimal ultrasound image are disclosed. In one embodiment, by way of
non-limiting example, a processing unit is configured perform an image
process upon an ultrasound image to thereby detect a center of a blood
vessel from the ultrasound image. The processing unit is configured to
set the center of the blood vessel as an optimal focal point position.
The processing unit is configured to calculate a plurality of steering
angles, a plurality of transmit (Tx) frequencies and a plurality of sound
speeds. The processing unit is further configured to form a plurality of
ultrasound images corresponding to each of the steering angles, the Tx
frequencies and the sound speeds based on the ultrasound data, detect a
signal to noise ratio (SNR), a number of edge points of the blood vessel
and a contrast difference between pixels for each of the second
ultrasound images to thereby detect an optimal steering angle, an optimal
Tx frequency and an optimal sound speed.

Claims:

1. An ultrasound system, comprising: an ultrasound data acquisition unit
configured to transmit and receive ultrasound signals to and from a
target object including a blood vessel to thereby output ultrasound data;
and a processing unit in communication with the ultrasound data
acquisition unit and being configured to form an ultrasound image based
on the ultrasound data, perform an image process upon the ultrasound
image to thereby detect a center of the blood vessel from the ultrasound
image, set the center of the blood vessel as an optimal focal point
position, and calculate a plurality of steering angles, a plurality of
transmit (Tx) frequencies and a plurality of sound speeds, wherein the
ultrasound data acquisition unit is further configured to transmit and
receive ultrasound signals to and from the target object in consideration
of each of the steering angles, the Tx frequencies and the sound speeds
to thereby output a plurality of ultrasound data, wherein the processing
unit is further configured to form a plurality of ultrasound images
corresponding to each of the steering angles, the Tx frequencies and the
sound speeds based on the ultrasound data, detect a signal to noise ratio
(SNR), a number of edge points of the blood vessel and a contrast
difference between pixels for each of the second ultrasound images to
thereby set an optimal steering angle, an optimal Tx frequency and an
optimal sound speed based on the SNR, the number of edge points and the
contrast difference

[0002] The present disclosure generally relates to ultrasound systems, and
more particularly to setting an optimal image parameter for obtaining an
optimal ultrasound image in an ultrasound system.

BACKGROUND

[0003] An ultrasound system has become an important and popular diagnostic
tool since it has a wide range of applications. Specifically, due to its
non-invasive and non-destructive nature, the ultrasound system has been
extensively used in the medical profession. Modern high-performance
ultrasound systems and techniques are commonly used to produce two or
three-dimensional diagnostic images of internal features of a target
object (e.g., human organs).

[0004] The ultrasound system can transmit and receive ultrasound signals
to and from a target object to thereby form 2D (two-dimensional) or 3D
(three-dimensional) ultrasound images of the target object.

[0005] The ultrasound system can form an optimal 2D or 3D ultrasound image
based on an optimal image parameter. The optimal image parameter may
include a focal point position, a steering angle, a transmit (Tx)
frequency, a sound speed and the like. However, in the conventional
ultrasound system, the optimal image parameter is set manually, not
automatically. That is, a complicated manual set is required to optimize
the 2D or 3D ultrasound image. Thus, diagnostic time becomes
significantly longer.

SUMMARY

[0006] Embodiments for adaptively setting an optimal image parameter in an
ultrasound system are disclosed herein. In one embodiment, by way of
non-limiting example, an ultrasound system comprises: an ultrasound data
acquisition unit configured to transmit and receive ultrasound signals to
and from a target object including a blood vessel to thereby output
ultrasound data and a processing unit in communication with the
ultrasound data acquisition unit and being configured to form an
ultrasound image based on the ultrasound data, perform an image process
upon the ultrasound image to thereby detect a center of the blood vessel
from the ultrasound image, set the center of the blood vessel as an
optimal focal point position, and calculate a plurality of steering
angles, a plurality of transmit (Tx) frequencies and a plurality of sound
speeds, wherein the ultrasound data acquisition unit is further
configured to transmit and receive ultrasound signals to and from the
target object in consideration of each of the steering angles, the Tx
frequencies and the sound speeds to thereby output a plurality of
ultrasound data, wherein the processing unit is further configured to
form a plurality of ultrasound images corresponding to each of the
steering angles, the Tx frequencies and the sound speeds based on the
ultrasound data, detect a signal to noise ratio (SNR), a number of edge
points of the blood vessel and a contrast difference between pixels for
each of the second ultrasound images to thereby set an optimal steering
angle, an optimal Tx frequency and an optimal sound speed based on the
SNR, the number of edge points and the contrast difference.

[0007] In another embodiment, there is provided a method of setting an
optimal image parameter, comprising: a) forming a first ultrasound image
based on ultrasound data for a target object including a blood vessel; b)
performing an image process upon the first ultrasound image to thereby
detect a center of the blood vessel from the first ultrasound image; c)
setting the center of the blood vessel as an optimal focal point
position; d) forming a plurality of second ultrasound images
corresponding to a plurality of steering angles for steering scan-lines,
wherein the steering angles are calculated by increasing/decreasing a
maximum steering angle by predetermined angles; e) detecting a signal to
noise ratio (SNR), a number of edge points of the blood vessel and a
contrast difference between pixels for each of the second ultrasound
images to thereby set an optimal steering angle based on the SNR, the
number of edge points and the contrast difference; f) forming a plurality
of third ultrasound images corresponding to a plurality of transmit (Tx)
frequencies, wherein the Tx frequencies are calculated by
increasing/decreasing a Tx frequency corresponding to the optimal
steering angel by predetermined frequencies; g) detecting the SNR, the
number of edge points and the contrast difference for each of the third
ultrasound images to thereby set an optimal Tx frequency based on the
SNR, the number of edge points and the contrast difference; h) forming a
plurality of fourth ultrasound images corresponding to a plurality of
sound speeds, wherein the sound speeds are calculated by
increasing/decreasing a reference sound speed by predetermined values;
and i) detecting the SNR, the number of edge points and the contrast
difference for each of the fourth ultrasound images to thereby set an
optimal sound speed based on the SNR, the number of edge points and the
contrast difference.

[0008] In yet another embodiment, there is provided a method of setting an
optimal image parameter, comprising: a) acquiring ultrasound data of a
target object including a blood vessel; b) forming an ultrasound image
based on the ultrasound data; c) performing an image process upon the
ultrasound image to thereby detect a center of the blood vessel from the
first ultrasound image; d) setting the center of the blood vessel as an
optimal focal point position; e) calculating a plurality of steering
angles, a plurality of transmit (Tx) frequencies and a plurality of sound
speeds; f) acquiring a plurality of ultrasound data of the target object
in consideration of each of the steering angles, the Tx frequencies and
the sound speeds; g) forming a plurality of ultrasound images
corresponding to each of the steering angles, the Tx frequencies and the
sound speeds based on the ultrasound data; h) detecting a signal to noise
ratio (SNR), a number of edge points of the blood vessel and a contrast
difference between pixels for each of the second ultrasound images to
thereby set an optimal steering angle, an optimal Tx frequency and an
optimal sound speed based on the SNR, the number of edge points and the
contrast difference.

[0009] The Summary is provided to introduce a selection of concepts in a
simplified form that are further described below in the Detailed
Description. This Summary is not intended to identify key or essential
features of the claimed subject matter, nor is it intended to be used in
determining the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a block diagram showing an illustrative embodiment of an
ultrasound system.

[0011]FIG. 2 is a graph showing an example of a grating lobe according to
transmit (Tx) frequencies.

[0012]FIG. 3 is a graph showing an example of optimal Tx frequencies set
according to image depths.

[0013]FIG. 4 is a schematic diagram showing an example of steering angles
set according to the image depths.

[0014] FIG. 5 is a graph showing an example of optimal Tx frequencies set
according to steering angles.

[0015]FIG. 6 is a schematic diagram showing an example of the optimal Tx
frequencies set according to the image depths and steering angles.

[0016]FIG. 7 is a block diagram showing an illustrative embodiment of an
ultrasound data acquisition unit.

[0017] FIGS. 8 and 9 are a flow chart showing a process for setting an
optimal image parameter according to a first embodiment of the present
invention.

[0018]FIG. 10 is a schematic diagram showing an example of an ultrasound
image, a region of interest (ROI) and a virtual rectangle.

[0019]FIG. 11 is a schematic diagram showing an example of the ultrasound
image, a seed point and the virtual rectangle.

[0020]FIG. 12 is a schematic diagram showing an example of a maximum
steering angle.

[0021]FIG. 13 is a flow chart showing a process for setting an optimal
image parameter according to a second embodiment of the present
invention.

DETAILED DESCRIPTION

[0022] A detailed description may be provided with reference to the
accompanying drawings. One of ordinary skill in the art may realize that
the following description is illustrative only and is not in any way
limiting. Other embodiments of the present invention may readily suggest
themselves to such skilled persons having the benefit of this disclosure.

[0023]FIG. 1 is a block diagram showing an illustrative embodiment of an
ultrasound system. Referring to FIG. 1, the ultrasound system 100 may
include a user input unit 110. The user input unit 110 may be configured
to receive input information from a user. In one embodiment, the input
information may include first input information for setting a region of
interest (ROI) on an ultrasound image or second input information for
setting a seed point on the ultrasound image. The ultrasound image may be
a brightness mode (B mode) image. However, it should be noted herein that
the ultrasound image may not be limited thereto. The user input unit 110
may include a control panel, a mouse, a keyboard and the like.

[0024] The ultrasound system 100 may further include a storage unit 120.
The storage unit 120 may store a blood vessel template corresponding to
an object of interest (e.g., blood vessel) within a target object.
Generally, the ultrasound system 100 may form an ultrasound image
including the blood vessel based on a specific application, for example,
a carotid application for observing the blood vessel. The blood vessel
has a different size at every target object but has, morphologically, a
unique and similar shape. Thus, the blood vessel template may be used to
detect the blood vessel in the ultrasound image.

[0025] The storage unit 120 may further store a mapping table including
transmit (Tx) frequencies and scan conditions. In one embodiment, the
scan conditions may include depths (hereinafter, image depths) from a
surface of the target object to a center of the blood vessel and steering
angles for steering a plurality of scan-lines. However, it should be
noted herein that the scan conditions may not be limited thereto.

[0026]FIG. 2 is a graph showing an example of a grating lobe according to
the transmit (Tx) frequencies. Generally, a grating lobe may mean
unwanted emission of ultrasound from electronic array transducers. The
grating lobe may be stronger as the Tx frequency becomes higher, as shown
in FIG. 2. Further, the grating lobe may be stronger as the steering
angle becomes larger (not shown).

[0027]FIG. 3 is a graph showing an example of optimal Tx frequencies
according to image depths. As shown in FIG. 3, a higher Tx frequency may
be set as the optimal Tx frequency when an image depth is smaller. Also,
a lower Tx frequency may be set as the optimal frequency when the image
depth is larger.

[0028]FIG. 4 is a schematic diagram showing an example of steering angles
set according to the image depths. As shown in FIG. 4, a larger steering
angle may be set when the image depth is smaller. Also, a smaller
steering angle may be set when the image depth is larger. That is,
steering angles θ1 to θ3 of scan-lines S1 to
Sn may be set in consideration of image depths d1 to d3
for a target object 210, as shown in FIG. 4.

[0029] FIG. 5 is a graph showing an example of optimal Tx frequencies set
according to the steering angles. As shown in FIG. 5, a lower Tx
frequency may be set as the optimal Tx frequency to decrease the grating
lobe when a steering angle is larger. Also, a higher Tx frequency may be
set as the optimal Tx frequency to decrease the grating lobe when the
steering angle is smaller, as shown in FIG. 5.

[0030]FIG. 6 is a schematic diagram showing an example of the optimal Tx
frequencies according to scan conditions (i.e., image depths and steering
angles). When only an image depth for a target object is considered to
set an optimal Tx frequency as in a conventional method, the resultant
values may be obtained as indicated in A shown in FIG. 6. Also, when only
a steering angle according to the image depth is considered to set an
optimal Tx frequency as in the conventional method, the resultant values
may be obtained as indicated in B, which is shown in FIG. 6. However, in
this embodiment, both the image depth and the steering angle are
considered to set an optimal Tx frequency.

[0031] When an image depth for the target object is less than a
predetermined threshold value C (i.e., the target object is located on a
near position from a surface of a subject, e.g., a patient), the optimal
Tx frequency is set according to the steering angle as shown in FIG. 6 to
decrease the grating lobe. Also, when the image depth for the target
object is more than the predetermined threshold value C (i.e., the target
object is located on a far position from the surface of the subject), the
optimal Tx frequency is set according to the image depth as shown in FIG.
6 to decrease the grating lobe.

[0032] In one embodiment, the mapping table is a table for setting the Tx
frequency in consideration of the steering angles when the image depth is
less than the predetermined threshold value and setting the Tx frequency
in consideration of the image depth when the image depth is more than the
predetermined threshold value.

[0033] Referring back to FIG. 1, the ultrasound system 100 may further
include an ultrasound data acquisition unit 130. The ultrasound data
acquisition unit 130 may be configured to transmit and receive ultrasound
signals to and from the target object to thereby output ultrasound data.

[0034]FIG. 7 is a block diagram showing an illustrative embodiment of the
ultrasound data acquisition unit. Referring to FIG. 7, the ultrasound
data acquisition unit 130 may include a transmit (Tx) signal generating
section 710, an ultrasound probe 720, a beam former 730 and an ultrasound
data forming section 740.

[0035] The Tx signal generating section 710 may be configured to generate
Tx signals for obtaining the ultrasound image.

[0036] The ultrasound probe 720 may include a plurality of elements (not
shown) for reciprocally converting between ultrasound signals and
electrical signals. The ultrasound probe 720 may be configured to form
ultrasound signals in response to the Tx signals provided from the Tx
signal generating section 710 to thereby transmit the ultrasound signals
into the target object. The ultrasound probe 720 may further receive
ultrasound echo signals reflected from the target object to thereby form
received signals. The received signals may be analog signals. The
ultrasound probe 720 may include a linear probe, a convex probe, a 3D
(three-dimensional) mechanical probe, a 2D (two-dimensional) array probe
and the like. However, it should be noted herein that the ultrasound
probe 720 may not be limited thereto.

[0037] The beam former 730 may be configured to convert the received
signals provided from the ultrasound probe 720 into digital signals. The
beam former 730 may further apply delays to the digital signals in
consideration of distance between the elements and focal points to
thereby output digital receive-focused signals.

[0038] The ultrasound data forming section 740 may be configured to form
the ultrasound data based on the digital receive-focused signals provided
from the beam former 730. The ultrasound data may be radio frequency (RF)
data or in-phase/quadrature (IQ) data. However, it should be noted herein
that the ultrasound data may not be limited thereto.

[0039] Referring back to FIG. 1, the ultrasound system 100 may further
include a processing unit 140 in communication with the user input unit
110, the storage unit 120 and the ultrasound data acquisition unit 130.
The processing unit 140 may be configured to form the ultrasound image
based on the ultrasound data provided from the ultrasound data
acquisition unit 130. The processing unit 140 may further analyze the
ultrasound image to thereby set an optimal image parameter for obtaining
an optimal ultrasound image. The image parameter may include a focal
point position, a steering angle, a transmit (Tx) frequency and a sound
speed. However, it should be noted herein that the image parameter may
not be limited thereto.

[0040] The ultrasound system 100 may further comprise a display unit 150.
The display unit 150 may display the ultrasound image formed by the
processing unit 140. The display unit 150 may include a cathode ray tube
(CRT), a liquid crystal display (LCD), an organic light emitting diodes
(OLED) and the like. However, it should be noted herein that the display
unit 150 may not be limited thereto.

[0041] Embodiments for setting the optimal image parameter may be
described with reference to the accompanying drawings.

FIRST EMBODIMENT

[0042] FIGS. 8 and 9 are flow charts showing a process of setting the
optimal image parameter according to a first embodiment of the present
invention. Referring to FIG. 8, the ultrasound data acquisition unit 130
may transmit and receive ultrasound signals to and from the target object
in consideration of a predetermined image parameter (hereinafter, a first
image parameter) to thereby output first ultrasound data at step S802.

[0043] More particularly, the Tx signal generating section 710 may
generate first Tx signals for obtaining the ultrasound image in
consideration of the first image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to the first Tx signals provided
from the Tx signal generating section 710. The ultrasound probe 720 may
further receive ultrasound echo signals reflected from the target object
to thereby form first received signals. The beam former 730 may convert
the first received signals provided from the ultrasound probe 720 into
first digital signals. The beam fanner 730 may further apply delays to
the first digital signals in consideration of the first image parameter
and the locations of the transducer elements to thereby output first
digital receive-focused signals. The ultrasound data forming section 740
may form the first ultrasound data based on the first digital
receive-focused signals provided from the beam former 730.

[0044] The processing unit 140 may form a first ultrasound image based on
the first ultrasound data provided from the ultrasound data acquisition
unit 130 at step S804. The first ultrasound image may be displayed on the
display unit 150.

[0045] The processing unit 140 may perform an image process upon the first
ultrasound image to thereby detect a center of the blood vessel at step
S806.

[0046] As one example, the processing unit 140 may retrieve the blood
vessel template from the storage unit 120. The processing unit 140 may
further locate the blood vessel template on the first ultrasound image.
The processing unit 140 may further detect the blood vessel in the first
ultrasound image while moving the blood vessel template by predetermined
intervals. The blood vessel may be detected by using image processing
methods such as a pattern matting method, a sum of absolute difference
(SAD) method and the like. However, it should be noted herein that the
image processing methods may not be limited thereto. The processing unit
140 may further detect a maximum diameter of the detected blood vessel.
The processing unit 140 may further detect a center of the maximum
diameter to thereby set the center of the maximum diameter as the center
of the blood vessel.

[0047]FIG. 10 is a schematic diagram showing an example of the first
ultrasound image, the ROI and a virtual rectangle. As another example,
the processing unit 140 may set the ROI 1030 on the first ultrasound
image 1010 based on the input information (i.e., first input information)
provided from the user input unit 110, as shown in FIG. 10. The
processing unit 140 may further detect a center 1040 of the ROI 1030. The
processing unit 140 may further detect edge points 1051, 1052, 1053 and
1054 corresponding to the blood vessel wall 1020 while moving the center
1040 to each of up, down, right and left directions by predetermined
intervals within the ROI 1030. The edge points 1051, 1052, 1053 and 1054
may have a maximum brightness difference between adjacent pixels in the
first ultrasound image. Also, methods of detecting the edge points are
well known in the art. Thus, they have not been described in detail so as
not to unnecessarily obscure the present invention. The processing unit
140 may further set the virtual rectangle 1060 passing through the edge
points 1051, 1052, 1053 and 1054. The processing unit 140 may further
detect a center of the virtual rectangle 1060 to thereby set the center
of the virtual rectangle 1060 as the center of the blood vessel.

[0048]FIG. 11 is a schematic diagram showing an example of the first
ultrasound image, a seed point and the virtual rectangle. As yet another
example, the processing unit 140 may set the seed point 1130 on the first
ultrasound image 1110 based on the input information (i.e., second input
information) provided from the user input unit 110, as shown in FIG. 11.
The processing unit 140 may further detect edge points 1141, 1142, 1143
and 1144 corresponding to the blood vessel wall 1120 while moving the
seed point 1130 to each of up, down, right and left directions by
predetermined intervals. The edge points 1141, 1142, 1143 and 1144 may
have a maximum brightness difference between adjacent pixels in the first
ultrasound image. The processing unit 140 may further set the virtual
rectangle 1150 passing through the edge points 1141, 1142, 1143 and 1144.
The processing unit 140 may detect a center of the virtual rectangle 1150
to thereby set the center of the virtual rectangle 1150 as the center of
the blood vessel.

[0049] Referring back to FIG. 8, the processing unit 140 may form a second
image parameter with the focal point position as the center of the blood
vessel at step S808. The steering angle, Tx frequency and sound speed of
the second image parameter correspond to the steering angle, Tx frequency
and sound speed of the first image parameter, respectively. The second
image parameter may be stored in the storage unit 120.

[0050] The processing unit 140 may calculate a maximum steering angle of
scan-lines at step S810. As one example, the processing unit 140 may
calculate a steering angle θ of a first scan-line S1 passing
through a vertex 1211 of the virtual rectangle 1060 or 1140 within the
scan-lines S1 to SN, as shown in FIG. 12. The processing unit
140 may further set the steering angle θ as the maximum steering
angle. As another example, the processing unit 140 may calculate a
steering angle θ of a last scan-line SN passing through a
vertex 1212 of the virtual rectangle 1060 or 1140 within the scan-lines
S1 to SN, as shown in FIG. 12.

[0051] The processing unit 140 may calculate a plurality of steering
angles based on the maximum steering angle at step S812. The steering
angles may be calculated by increasing and/or decreasing the maximum
steering angle by predetermined angles.

[0052] The ultrasound data acquisition unit 130 may transmit and receive
ultrasound signals to and from the target object in consideration of the
second image parameter and the steering angles to thereby output a
plurality of second ultrasound data at step S814.

[0053] More particularly, the Tx signal generating section 710 may
generate a plurality of second Tx signals for obtaining a plurality of
second ultrasound images corresponding to the steering angles in
consideration of the second image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to each of the second Tx signals
provided from the Tx signal generating section 710. The ultrasound probe
720 may further receive ultrasound signals reflected from the target
object to thereby form a plurality of second received signals. The beam
former 730 may convert the second received signals provided from the
ultrasound probe 720 into a plurality of second digital signals. The beam
former 730 may further apply delays to the second digital signals in
consideration of the second image parameter, the steering angles and the
locations of the transducer elements to thereby output a plurality of
second digital receive-focused signals. The ultrasound data forming
section 740 may form the second ultrasound data based on the second
digital receive-focused signals.

[0054] The processing unit 140 may form the second ultrasound images based
on the second ultrasound data provided from the ultrasound data
acquisition unit 130 at step S816. The second ultrasound images may be
displayed on the display unit 150.

[0055] The processing unit 140 may analyze the second ultrasound images to
thereby detect an optimal steering angle from the plurality of steering
angles at step S818.

[0056] As one example, the processing unit 140 may set a window having a
predetermined size based on the detected blood vessel on each of the
second ultrasound images. The processing unit 140 may further detect a
signal to noise ratio (SNR), a number of edge points of the blood vessel
and a contrast difference between pixels for the window. The processing
unit 140 may further rate each of the detected SNR, the number of edge
points and the contrast difference for each of the second ultrasound
images. For example, if the SNR is -10 dB to -15 dB, then the SNR may be
rated to 10. If the SNR is -16 dB to -30 dB, then the SNR may be rated to
5. Also, if the SNR is -31 dB to -40 dB, then the SNR may be rated to 0.
In addition, if the number of edge points is less than 10, then the
number of edge points may be graded to 0, If the number of edge points is
10 to 20, then the number of edge points may be rated to 5. Moreover, if
the number of edge points is more than 21, then the number of edge points
may be rated to 10. Further, if the contrast difference is less than 30,
then the contrast difference may be rated to 0. If the contrast
difference is 31 to 60, then the contrast difference may be rated to 5.
If the contrast difference is more than 60, then the contrast difference
may be rated to 10. The processing unit 140 may further compare the rated
points of each of the second ultrasound images to thereby detect a second
ultrasound image having a maximum point. The processing unit 140 may set
the steering angle corresponding to the detected second ultrasound image
as the optimal steering angle.

[0057] The processing unit 140 may form a third image parameter with the
steering angle as the optimal steering angle at step 820. The focal point
position, Tx frequency and sound speed of the third image parameter
correspond to the focal point position, Tx frequency and sound speed of
the second image parameter, respectively. The third image parameter may
be stored in the storage unit 120.

[0058] The processing unit 140 may retrieve a Tx frequency corresponding
to the center of the blood vessel and the optimal steering angle from the
storage unit 120, as shown in FIG. 6, at step S822.

[0059] The processing unit 140 may calculate a plurality of Tx frequencies
based on the retrieved Tx frequency at step S824. The Tx frequencies may
be calculated by increasing and/or decreasing the retrieved Tx frequency
by predetermined frequencies.

[0060] Referring to FIG. 9, the ultrasound data acquisition unit 130 may
transmit and receive ultrasound signals to and from the target object in
consideration of the third image parameter and the Tx frequencies to
thereby output a plurality of third ultrasound data at step S902.

[0061] More particularly, the Tx signal generating section 710 may
generate a plurality of third Tx signals for obtaining a plurality of
third ultrasound images corresponding to the Tx frequencies in
consideration of the third image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to each of the third Tx signals
provided from the Tx signal generating section 710. The ultrasound probe
720 may further receive ultrasound echo signals reflected from the target
object to thereby form a plurality of third received signals. The beam
former 730 may convert the third received signals provided from the
ultrasound probe 720 into a plurality of third digital signals. The beam
former 730 may further apply delays to the third digital signals in
consideration of the third image parameter and the locations of the
transducer elements to thereby output a plurality of third digital
receive-focused signals. The ultrasound data forming section 740 may form
the third ultrasound data based on the third digital receive-focused
signals.

[0062] The processing unit 140 may form the third ultrasound images based
on the third ultrasound data provided from the ultrasound data
acquisition unit 130 at step S904.

[0063] The processing unit 140 may analyze the third ultrasound images to
thereby detect an optimal Tx frequency from the Tx frequencies at step
S906. The method of detecting the optimal Tx frequency is similar to the
method of detecting the optimal steering angle at step S818 in FIG. 8.
Thus, it has not been described in detail.

[0064] The processing unit 140 may form a fourth image parameter with the
Tx frequency as the optimal Tx frequency at step S908. The focal point
position, steering angle and sound speed of the fourth image parameter
correspond to the focal point position, steering angle and sound speed of
the third image parameter, respectively. The fourth image parameter may
be stored in the storage unit 120.

[0065] The processing unit 140 may calculate a plurality of sound speeds
based on a reference sound speed (e.g., 1564 m/s) at step S910. The sound
speeds may be calculated by increasing and/or decreasing the reference
sound speed by predetermined intervals.

[0066] The ultrasound data acquisition unit 130 may transmit and receive
ultrasound signals to and from the target object in consideration of the
fourth image parameter and the sound speeds to thereby output a plurality
of fourth ultrasound data at step S912.

[0067] More particularly, the Tx signal generating section 710 may
generate a plurality of fourth Tx signals for obtaining a plurality of
fourth ultrasound images corresponding to the sound speeds in
consideration of the fourth image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to each of the fourth Tx signals
provided from the Tx signal generating section 710. The ultrasound probe
720 may further receive ultrasound echo signals reflected from the target
object to thereby form a plurality of fourth received signals. The beam
former 730 may convert the fourth received signals provided from the
ultrasound probe 720 into a plurality of fourth digital signals. The beam
former 730 may further apply delays to the fourth digital signals in
consideration of the fourth image parameter and the locations of the
transducer elements to thereby output a plurality of fourth digital
receive-focused signals. The ultrasound data forming section 740 may form
the fourth ultrasound data based on the fourth digital receive-focused
signals.

[0068] The processing unit 140 may form a plurality of fourth ultrasound
image based on the fourth ultrasound data provided from the ultrasound
data acquisition unit 130 at step S914.

[0069] The processing unit 140 may analyze the fourth ultrasound images to
thereby detect an optimal sound speed from the sound speeds at step S916.
The method of detecting the optimal sound speed is similar to the method
of detecting the optimal steering angle at step S818 in FIG. 8. Thus, it
has not been described in detail.

[0070] The processing unit 140 may form a fifth image parameter with the
sound speed as the optimal sound speed at step S918. The focal point
position, steering angle and Tx frequency of the fifth image parameter
correspond to the focal point position, steering angle and Tx frequency
of the fourth image parameter, respectively. The processing unit 140 may
set the fifth image parameter as the optimal image parameter at step
S920. The optimal image parameter may be stored in the storage unit 120.

[0071] The ultrasound data acquisition unit 130 may transmit and receive
ultrasound signals to and from the target object in consideration of the
optimal image parameter to thereby form fifth ultrasound data at step
S922.

[0072] More particularly, the Tx signal generating section 710 may
generate fifth Tx signals for obtaining an optimal ultrasound image in
consideration of the optimal image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to the fifth Tx signals provided
from the Tx signal generating section 710. The ultrasound probe 720 may
further receive ultrasound echo signals reflected from the target object
to thereby form fifth received signals. The beam former 730 may convert
the fifth received signals provided from the ultrasound probe 720 into
fifth digital signals. The beam former 730 may further apply delays to
the fifth digital signals in consideration of the optimal image parameter
and the locations of the transducer elements to thereby output fifth
digital receive-focused signals. The ultrasound data forming section 740
may form the fifth ultrasound data based on the fifth digital
receive-focused signals.

[0073] The processing unit 140 may form the optimal ultrasound image based
on the fifth ultrasound data provided from the ultrasound data
acquisition unit 130 at step S924.

[0074] The display unit 150 may display the optimal ultrasound image
formed by the processing unit 140 at step S926.

[0075] While the image parameter may be optimized in order of the focal
point position, the steering angle, the Tx frequency and the sound speed,
the image parameter may be further optimized in various order of the
focal point position, the steering angle, the Tx frequency and the sound
speed as occasion demands.

SECOND EMBODIMENT

[0076]FIG. 13 is a flow chart showing a process of setting an optimal
image parameter according to a second embodiment of the present
invention. Referring to FIG. 13, the ultrasound data acquisition unit 130
may transmit and receive ultrasound signals to and from the target object
in consideration of the first image parameter to thereby output the first
ultrasound data at step S1302. The step S1302 in the second embodiment is
similar to the step S802 in the first embodiment. Thus, it has not been
described in detail.

[0077] The processing unit 140 may form the first ultrasound image based
on the first ultrasound data provided form the ultrasound data
acquisition unit 130 at step S1304. The first ultrasound image may be
displayed on the display unit 150.

[0078] The processing unit 140 may analyze the first ultrasound image to
thereby detect the center of the blood vessel at step S1306. The step
S1306 in the second embodiment is similar to the step S806 in the first
embodiment. Thus, it has not been described in detail.

[0079] The processing unit 140 may form the second parameter with the
focal point position as the center of the blood vessel at step S1308. The
steering angle, Tx frequency and sound speed of the second image
parameter correspond to the steering angle, Tx frequency and sound speed
of the first image parameter, respectively. The second image parameter
may be stored in the storage unit 120.

[0080] The processing unit 140 may calculate the maximum steering angle of
the scan-lines at step S1310. The step S1310 in the second embodiment is
similar to the step S810. Thus, it has not been described in detail.

[0081] The processing unit 140 may calculate the steering angles based on
the maximum steering angle at step S1312. The steering angles may be
calculated by increasing and/or decreasing the maximum steering angle by
predetermined angles.

[0082] The processing unit 140 may retrieve a Tx frequency corresponding
to the center of the blood vessel and the maximum steering angle from
storage unit 120, as shown in FIG. 6, at step S1314. The processing unit
140 may calculate a plurality of Tx frequencies based on the retrieved Tx
frequencies at the step S1316.

[0083] The processing unit 140 may calculate a plurality of sound speeds
based on a reference sound speed (e.g., 1564 m/s) at step S1318. The
sound speeds may be calculated by increasing and/or decreasing the
reference sound speed by predetermined values.

[0084] The ultrasound data acquisition unit 130 may transmit and receive
ultrasound signals to and from the target object in consideration of the
second image parameter, the steering angles, the Tx frequencies and the
sound speeds to thereby output a plurality of sixth ultrasound data at
step S1320.

[0085] More particularly, the Tx signal generating section 710 may
generate a plurality of sixth Tx signals corresponding to the steering
angles, the Tx frequencies and the sound speeds in consideration of the
second image parameter and the locations of the transducer elements. The
ultrasound probe 720 may transmit ultrasound signals to the target object
in response to each of the sixth Tx signals provided from the Tx signal
generating section 710. The ultrasound probe 720 may further receive
ultrasound echo signals reflected from the target object to thereby form
a plurality of sixth received signals. The beam former 730 may convert
the sixth received signals provided from the ultrasound probe 720 into a
plurality of sixth digital signals. The beam former 730 may further apply
delays to the sixth digital signals in consideration of the second image
parameter and the locations of the transducer elements to thereby output
a plurality of sixth digital receive-focused signals. The ultrasound data
forming section 740 may form the sixth ultrasound data based on the sixth
digital receive-focused signals.

[0086] The processing unit 140 may fowl a plurality of sixth ultrasound
images based on the sixth ultrasound data provided from the ultrasound
data acquisition unit 130 at step S1322.

[0087] The processing unit 140 may analyze the sixth ultrasound images to
thereby detect the optimal steering angle, the optimal Tx frequency and
the optimal sound speed at step S1324.

[0088] In one embodiment, the processing unit 140 may set a window having
a predetermined size based on the detected blood vessel on each of the
sixth ultrasound images. The processing unit 140 may further detect a
signal to noise ratio (SNR), a number of edge points of the blood vessel
and a contrast difference between pixels for the window. The processing
unit 140 may further rate each of the detected SNR, the number of edge
points and contrast difference for each of the sixth ultrasound images.
For example, if the SNR is -10 dB to -15 dB, then the SNR may be rated to
10. If the SNR is -16 dB to -30 dB, then the SNR may be rated to 5. If
the SNR is -31 dB to -40 dB, then the SNR may be rated to 0. In addition,
if the number of edge points is less than 10, then the number of edge
points may be graded to 0. If the number of edge points is 10 to 20, then
the number of edge points may be rated to 5. If the number of edge points
is more than 21, then the number of edge points may be rated to 10.
Further, if the contrast difference is less than 30, then the contrast
difference may be rated to 0. If the contrast difference is 31 to 60,
then the contrast difference may be rated to 5. If the contrast
difference is more than 60, then the contrast difference may be rated to
10. The processing unit 140 may further compare the rated points of each
of the sixth ultrasound images to thereby detect a sixth ultrasound image
having a maximum point. The processing unit 140 may set the steering
angle, the Tx frequency and the sound speed corresponding to the detected
sixth ultrasound image as the optimal steering angle, the optimal Tx
frequency and the optimal sound speed, respectively.

[0089] The processing unit 140 may form an optimal image parameter based
on the optimal steering angle, the optimal Tx frequency and the optimal
sound speed at step S1326. The focal point position of the optimal image
parameter corresponds to the focal point position of the second image
parameter.

[0090] The ultrasound data acquisition unit 130 may transmit and receive
ultrasound signals to and from the target object in consideration of the
optimal image parameter to thereby form seventh ultrasound data at step
S1328.

[0091] More particularly, the Tx signal generating section 710 may
generate seventh Tx signals for obtaining an optimal ultrasound image in
consideration of the optimal image parameter and the locations of the
transducer elements. The ultrasound probe 720 may transmit ultrasound
signals to the target object in response to the seventh Tx signals
provided from the Tx signal generating section 710. The ultrasound probe
720 may further receive ultrasound echo signals reflected from the target
object to thereby form seventh received signals. The beam former 730 may
convert the seventh received signals provided from the ultrasound probe
720 into seventh digital signals. The beam former 730 may further apply
delays to the seventh digital signals in consideration of the optimal
image parameter and the locations of the transducer elements to thereby
output seventh digital receive-focused signals. The ultrasound data
forming section 740 may form the seventh ultrasound data based on the
seventh digital receive-focused signals.

[0092] The processing unit 140 may form the optimal ultrasound image based
on the seventh ultrasound data provided from the ultrasound data
acquisition unit 130 at step S1330.

[0093] The display unit 150 may display the optimal ultrasound image
formed by the processing unit 140 at step S1332.

[0094] Although embodiments have been described with reference to a number
of illustrative embodiments thereof, it should be understood that
numerous other modifications and embodiments can be devised by those
skilled in the art that will fall within the spirit and scope of the
principles of this disclosure. More particularly, numerous variations and
modifications are possible in the component parts and/or arrangements of
the subject combination arrangement within the scope of the disclosure,
the drawings and the appended claims. In addition to variations and
modifications in the component parts and/or arrangements, alternative
uses will also be apparent to those skilled in the art.

Patent applications by Dong Kuk Shin, Seoul KR

Patent applications by Sang Shik Park, Seoul KR

Patent applications by Medison Co., Ltd.

Patent applications in class Anatomic image produced by reflective scanning

Patent applications in all subclasses Anatomic image produced by reflective scanning